[Extensions] Remove JSONFeatureProvider, SimpleFeature::Parse

extensions/common/features/permission_feature.cc

Index: extensions/common/features/permission_feature.cc
diff --git a/extensions/common/features/permission_feature.cc b/extensions/common/features/permission_feature.cc
index 27d18740c11780ec2ca0fc8703b0e996b88735a7..fe63041dc841a28489a60656e84effd3ba709017 100644
--- a/extensions/common/features/permission_feature.cc
+++ b/extensions/common/features/permission_feature.cc
@@ -33,22 +33,4 @@ Feature::Availability PermissionFeature::IsAvailableToContext(
   return CreateAvailability(IS_AVAILABLE);
 }
 
-bool PermissionFeature::Validate(std::string* error) {
-  if (!SimpleFeature::Validate(error))
-    return false;
-
-  if (extension_types().empty()) {
-    *error = name() + ": Permission features must specify at least one " +
-             "value for extension_types.";
-    return false;
-  }
-
-  if (!contexts().empty()) {
-    *error = name() + ": Permission features do not support contexts.";
-    return false;
-  }
-
-  return true;
-}
-
 }  // namespace extensions